Fine-Grained Analysis of Cache-Enabled Multiantenna Networks With Interference Nulling

This article provides a fine-grained performance analysis of a multiantenna cache-enabled network with interference nulling (IN) employed at base stations. Two IN schemes, namely, the fixed IN scheme and the flexible IN scheme are considered to improve the received signal-to-interference ratio (SIR) at users. To thoroughly explore the effects of the caching parameter and the IN parameters on the network performance, we focus on the analysis of not only the successful transmission probability (STP) but the link reliability distribution. First, the expression for the STP of each IN scheme is derived. Then, for the link reliability analysis of each IN scheme, an approximation for the SIR metadistribution is obtained by deriving the first and second moments of an upper bound of the link reliability and utilizing the beta distribution, and an approximated expression for the variance of link reliability is also derived. With this analytical framework, we compare the performance of these two IN schemes and gain some useful system design guidelines from the perspectives of STP and the link reliability distribution.